1. Field of the Invention
This invention relates generally to exercise machines, and more particularly to an exercise machine producing an elliptical motion emulating a stepping, or climbing motion.
2. Description of Related Art
The following art defines the present state of this field:
Miller, et. al. U.S. Pat. No. 5,242,343 describes an exercise device including a pair of foot engaging links. The first end of each link is supported for rotational motion about a pivot axis and a second end of each foot link is guided in a reciprocal path of travel. The combination of these foot link motions permits the user's foot to travel in an inclined, oval path of travel. This natural foot action exercises a large number of muscles through a wide range of motion.
Rodgers, Jr. et. al. U.S. Pat. No. 5,549,526 describes a stationary exercising device that promotes cardiovascular exercise yet minimizes impact to critical joints, particularly the ankles and knees. A frame supports a linkage assembly having at least one linkage member with a camming surface. The linkage assembly is in turn connected to a coupling system attached to the frame. Structure is included which permits each foot of the user to move the linkage assembly in such a manner as to generate a preferred closed path movement for the foot in a preferred anatomical pattern minimizing unnecessary stress in the joints, yet permitting a cardiovascular workout. Whan-Tong, et al. U.S. Pat. No. 5,685,804 describes an exercise device including a pair of foot engaging links (30a, 30b). The rearward ends of the foot links are supported for rotational motion about a pivot axis (26), and the forward ends of the foot links reciprocate back and forth along a guide (36). The combination of these two foot link motions permit the user's feet to travel along an elliptical path of travel. The inclination and/or elevation of the guide (36) may be selectively altered to vary the nature of the stepping motion experienced by the user. At lower inclinations/elevations of the guide, the stepping motion may resemble cross-country skiing. At progressively higher angles of inclination or elevations of the guide (36), the stepping motions may simulate walking, jogging, running and climbing. The connection of the foot links to the pivot axis allows motion in a direction orthogonal to the rotational motion, thus compensating for alignment inconsistencies of the device.
Miller, et al. U.S. Pat. No. 5,383,829 describes an exercise device including a pair of foot engaging links. The first end of each link is supported for rotational motion about a pivot axis and a second end of each foot link is guided in a reciprocal path of travel. The combination of these foot link motions permits the user's foot to travel in an inclined, oval path of travel. This natural foot action exercises a large number of muscles through a wide range of motion.
Miller, et. al. U.S. Pat. No. 5,562,574 describes a compact exercise device including a pair of crank arms pivotably supported on a frame for rotation about a pivot axis. Each crank arm engages a respective intermediate link at its first end. A second end of each intermediate link travels on a guide member so that as the crank arms rotates, the first end of each intermediate link traces an arcuate path, and the second end of each intermediate link traces a reciprocating path. The device includes a pair of foot links, each foot link coupled, through a first end thereof, to a respective one of said intermediate links at a point between the first and second ends thereof. A second end of each foot link engages another guide member that directs it along a preselected path of travel, as the intermediate link is moved by the crank arm. The device provides a range of foot and leg motion simulating a natural running and stepping action.
Stearns, et. al. U.S. Pat. No. 5,290,211 describes an exercise device (10) having foot supports (30, 32) on which a user stands for performing a stair stepping exercise alone, or a cross country skiing exercise alone, or simultaneously a stair stepping exercise and a cross country skiing exercise. Linkage support frames (26, 28) each have a first linkage (44) and a second linkage (36) are pivotally connected to each other for maintaining foot supports (30, 32) in a horizontal plane. A fluid cylinder (52) provides a mechanism for resisting the vertical movement of the foot supports (30, 32). Manually gripped poles (60) are mounted to move in coordination with generally horizontal movement of foot supports (30, 32). Separate embodiments of the invention are illustrated in FIGS. 5-13, showing how the invention may be used for performing a stair stepping exercise, a cross-country skiing exercise or walking exercise. An alternative preferred embodiment of the invention that may be folded downwardly for low vertical profile storage is illustrated in FIG. 14.
Miller, et. al. U.S. Pat. No. 5,577,985 describes an exercise device includes a frame having a set of guide links pivotally supported thereupon. Each guide link supports a foot-engaging link at one end thereof. The guide links are reciprocated back and forth by a set of intermediate links that engage a set of cranks that rotate about a second pivot point. A control link joins the foot link to the intermediate link and operates to vary the angle between the guide links and the foot links, as the guide links reciprocate. This device provides a very natural running and stepping action for a user who is positioned on the foot links.
Rodgers, Jr., et. al. U.S. Pat. No. 5,593,372 describes a stationary exercising apparatus which promotes cardiovascular exercise yet minimizes impact on critical joints through the generation of a predetermined elliptical path movement while maintaining foot platforms substantially parallel with the floor. A base structure supports a pair of reciprocating members which are displaced in a horizontal direction parallel with the floor at one end, yet reciprocate in circular motion at the other end through a coupling system attached to the frame. A linkage assembly is included which operates in conjunction with the reciprocation of one end of the reciprocating members to maintain the foot platforms substantially parallel with a reference plane while revolving the foot platforms in a substantially elliptical path. The apparatus may include additional linkage to facilitate a corresponding upper body exercise involving movement of the arms along a predetermined arc.
Rodgers, Jr. et. al. U.S. Pat. No. 5,593,371 describes a stationary exercising device that promotes cardiovascular exercise yet minimizes impact to critical joints, particularly the ankles and knees. A frame supports a linkage assembly having at least one linkage member with a camming surface. The linkage assembly is in turn connected to a coupling system attached to the frame. Structure is included which permits each foot of the user to move the linkage assembly in such a manner as to generate a preferred closed path movement for the foot in a preferred anatomical pattern, minimizing unnecessary stress in the joints yet permitting a cardiovascular workout.
Habing, et al. U.S. Pat. No. 5,499,956 describes an exercise machine having a pair of laterally spaced apart foot pedals, each of which is independently coupled to a frame by a respective articulated linkage. Each such linkage has a generally vertical arm that is pivotally coupled to the frame, and a generally horizontal arm that is pivotally coupled to its respective foot pedal. These arms are pivotally coupled to one another such that each foot pedal is free to move within a twodimensional envelope of motion in a vertical plane. The linkage members are arranged so that the envelope of motion has a generally ovate shape, slightly inclined to the horizontal. The exercises performed with this apparatus may have both vertical and horizontal components of motion. The vertical arms may be interconnected by a crank assembly to relate the horizontal components of motion of the two linkages in an alternating reciprocating fashion.
Rodgers, Jr. et. al. U.S. Pat. No. 5,529,555 describes a crank assembly for use within an exercising device that promotes cardiovascular exercise yet minimizes impact on critical joints, particularly the ankles and knees. The crank assembly employs a dual coupler system that is interconnected for synchronized rotation. Linkage assemblies are provided which define a predetermined path having preferred anatomical pattern for foot movement of the user. The crank assembly can be used in an exercising device that promotes leg exercise primarily, or can be combined with two additional linkage assemblies to provide a combined hand motion with leg movement. In this manner, an enhanced cardiovascular workout is provided which minimizes stress on key joints, particularly the ankles and knees.
Miller et. al. U.S. Pat. No. 5,518,473 describes an exercise device including a frame which supports a pair of foot links, so that a first end of each foot link is pivotably coupled to the frame for motion about an arcuate path. A guide that is supported by the frame engages each foot link, and directs a second end of each foot link along a closed, curved, generally teardrop-shaped path of travel. This combination of motions defined by the foot link provides a natural running and stepping motion in which the heel of a user's foot initially rises faster than the toe as the foot begins to move forward, and subsequently falls faster than the toe as the foot begins to move backward.
Blend, et al. U.S. Pat. No. 219,439 describes the combination of the adjustable brackets and round brackets and roller C D, the crank-shaft E, the pulleys and band F H G, the crank fly-wheels K, the connecting bars L, the cars M, and the tracks formed of the plates N, the bars O, and the switchbars P, with each other and with the framework A B.
The prior art teaches various stationary exercising devices which cause a user's feet to move in circular, elliptical, and backwards and forward movements, and all of which place the cranking means at the front or rear of the device, thereby limiting the diameter of the user's arcuate stride. Although one piece of prior art teaches a pivot point placed medially along a foot pedal, the resulting elliptical path traced by the stride occurs at an inclined angle. However, the prior art does not teach an exercise machine which places the cranking means at the midpoint of the reciprocating members, thereby causing the user to trace a longer elliptical stride than the prior art allows, and hence achieve greater benefits through exercise.
The present invention fulfills these needs and provides further related advantages as described in the following summary.